Dexter Morgan (Michael C. Hall) is a "blood-spatter" analyst who moonlights as a vigilante serial killer seeking justice against criminals who escape the law. Showtime's 'Dexter' begins its final season Sunday (9 ET/PT). Randy Tepper, Showtime

Walter White (Bryan Cranston), the high school chemistry teacher who turns meth dealer after being diagnosed with cancer, has developed into a full-fledged drug kingpin as AMC's 'Breaking Bad' readies its final season, due Aug. 11. Ursula Coyote, AMC